Differential mechanism



F. M. Lwls DIFFERENTIAL IIECHANISII Filed April 25, 1927 Aug. 2s', 192s.

4 Sheets-Sheet 2 Aug. za, 1928.

F. M,- LEwl's DIFFERENTIAL ucmmrsu Fnac; Apri; 2:5. 1927 4. Sheets-Shaq# 5 lll l-l l-l H H ping wheel. To obvate this fault, there Patented fitug. 28,- 1928.

UNITED STATES FRANK M. LEW'S, 0F CHICAGO, ILLINOIS.

DFFERENTAL MECHANISM. v

Application filed April 23, 1927. Serial No. 185,972.

Most automobiles and motor vehicles are equipped with what known as the standard or equalizing differential, consisting as to its essential parts of a rotating differential drum or housing driven from the propeller shaft by a bevel pinion orworin on the latter meshing` with la bevel gear or worin wheel on the drum, and bevel pinions journaled in the drum meshing on opposite sides with bevel gears keyed tothe inner ends of the two axle sections. lA serious practical fault with this differential gear lies in the fact that if either wheel slips through insufficient traction, no greater power can be applied to the opposite wheel than is afforded by the traction of the slipvhave been developed various forms of what is known asa locking differential; that is, one which permits the overrunning of either wheel, as in the case of the emializing7 differential, but wherein, if either wheel slips through insucient traction, the entire power ofthe motor is applied to the other wheel.

One object of my present inventionfis to provide a construction employing both of the above-named types of differential gearing, with means whereby either gearing may be used at will, or both gearings may be disconnected from the rear axle sections, so

as to permit the use of a power take-orf from the propeller shaft or some other elementV of the transmission without the necessity of jacking Vup the rear axle to raise either or both of the traction wheels from the ground in order to employ the power take-off to operate an appliance. that is not carried l by or traveling` with the motor vehicle itself.

Another obje-ft of the invention is to provide a rear axle gearing including an equalizing differential and of suoli a construction that the drive from the rotating drum or housing of the equali'zing. differential to one traction wheely can be disconnected and the power ofthe motor applied to the other traction wheel to rotate the latter at the same speed as the drum, instead of at double the speed and with half the power as occurs with the equalizing vdifferential gear alone where the drive is applied y with one wheel held against turning.

l ther objects and attendant advantages of the invention will be apparent to persons skilled in the art as the same becomes better understood by reference to the following de- -tailed description, taken in connection with ksection at the right;

lto its axle;

the accompanying drawings wherein ll have l illustrated simple and practical embodiments both an equalizing differential gearing and a locking differential gearing, with manually operable means fordisconnecting both gearings from the axle sections;

Fig. 2 is. a vertical section through the central enlarged portion of the rear axle housing or bridge and the rotating 'drum VVof `the locking differential, with partsof the latter shown in elevation at the left andv in Fig. 3 is a top plan view, with the upper portion of the rear axle housing broken out to disclose certain cams through whichnthe locking differential'may befmanually thrown out of gear on either or both sides;

Fig. 4l is a perspective elevation of one` of the laterally shiftable clutch members through which the axle driving gear of the equalizing differential is drivingly coupled Fig. 5 is a perspectiveelevation of a laterally shiftable clutch shifting sleeve. through which the throw-out of the shif'table clutch member shown in Figi is effected;

Fig. 6 isa. side elevation of' the main driv- .s

ing spider of both the equalizing and the standard differential gearings, showing also vin inner face view one ofthe laterally shiftable Vdriving clutch members of the locking` differential: j v Figf? is a vview-similar to Fig. 1, showing an equalizing differential gearing in combination Iwith mechanism for positively vclutching the sides lof the differential drum to and unclutching themfroin the respective axle sections ;v n p y y Fig. 8 is a sideelevation of the parts within the rearr axle housing or bridge of Fig.

,Xin section through one. of thea'xles on the line 8 8 of Fig. 7,*and partly Vbroken out Y.

to disclose rearwardly lying parts.

Beferring'to the embodiment ofthe invention shown in Figs.1 to y6 inclusive" 10 designates each of the central bell-shaped portions of the axle housing' or bridge within which the differential gearings are contained,

said parts being rigidly unitedby boltsll and formed with inner bearings '12 for the two axlesections 13. 14 is a propeller shaft journaled in a bearing 15 at the meeting line-,A

of the housing sections 10 and carrying a bevel pinion 16 meshing with and driving a master` gear 17 that is attached by bolts 18 and 19 to a rotary drum 20 ofthe locking differential, the bolts 19 serving also to unite the two sections of the drum V2O. Mounted on the inner meeting ends of the axle sections 13 is the hub 21 (Fig. 6) 'of a three-arm spider. the outer ends of the arms of .the spider being secured in mating seats formed in the meeting faces of the drum sections 2O, so that the spider is .positively rotated b y and from said drum. 'The' inner portion of each Varm of the spider lis formed as a bearing 22 for one of the bevel pinions '23 of the equalizing differential; said pinions 23 meshing on opposite sides wth bevel gears 24 which in the standard equa-lining differential are keyed to the .axle sections, but, in this case, are loose on the aXle sections. The bevel gears 24 are formed with outwardly extending-hubs 211", on which 'are rotatably mounted the mating sections A25 of the rotating drum of the equalizing,

differential, the inner faces of 'the drum sections 25 being formed with semi-circular seats to receive round portions of the spider Varm lying just outwardly of the Vbearing portions 22. y

The bevel gears 24 of the equalizing dif-V ferential are drivingly Vconnected to the axle sections 13 through mechanism which permits thedrive to be disconnected or finterrupted, as follows: `Keyed to the axle sections 13 beyond thehubs 24 of the bevel tgears 24 are a pair `oef driven clutch members 27 that are formed on their inner annular 'faces with clutch teeth 28. On the outer ends of the hubs 24" of the lgears 24 are V'formed wedge-shaped radial lugs 29 having oppositely sloping sides constituting whatlflterm maljor cams. Laterallyslidable on the axle sections 13 between 'the gears 24 and the driven clutch members 27 are driving clutchl members 30, one of which is shown in isolated detail .in Fig. 1. Each of these driving clutch members 30 is formed on its inner face with radial Vrecesses 31 Aformed with inclined -side walls that lit the bers 30, and the driven clutch members 27 to the axle lsections 13. This drive from both sides of the equalizing differential to the 'axle 'sections may be interrupted when desired by manually operated means hereinafter described.

Describing next the locking differential ygear,'by reference to Fig. 1 it will be seen `members of the locking diderential. 'The arms of the driving spider, just outside of the drum 25 are made hexagonal, to provide inclined forward driving faces 37 4and inclined rearward driving faces `33. 'These inclined or cam portions 37 and 38 of the spider arms coope ate with correspondingly shaped notches formed in the inner faces of a pair ofv laterally shiftable driving clutch rings 39 that are supported on bearings formed on the central portion of the drum 25; said recesses having inclined sidesll() (Fig. 2) engaged by the inclined sides '37 of the spiderarms for forward driving, and

vinclined sides 11 engaged by Vthe inclined sides 38 of the spiderarms for rearward driving. The laterally Vshiftable clutch rings 39 have on their outer sides yclutch teeth L,lf2 that cooperate with the clutch teeth 36 of the driven clutch members 35. rrhe driving clutch rings 39 are urged into `engagement with the vdriven clutch members 35 by thrust springs 43 (Fig. 2). Vbetween their opposed faces, and the extent 'of their relative tmningmovement is limited `by pins la (Fig. 17') in the face of one rin-g engaged in relatively .enlarged holes or slots 45 in `the other. The cam thrust of the inclined faces of the spider armszen the correspondingly inclined walls of the recesses maintains the driving clutch members 39 in werling engagement with the driven clutch members 35, but when one wheeloverruns the other, the teeth on the members 35 act as cams on. the teeth of the members 39 to force the latter inwardly. inward camming of the drivin-g clutch member 39 during overwinning, it essential to To effect this limit the rotary movement thereof (which is Y done by the pin 414 and hole 45) so that `the rear cams LOor a1 on the driving clutch member (with reference .to the direction spider arm, oppose such inward* of the equalizing dierential to the axlek grooved collar 46, the inner face of which abuts against a plurality of push rods 47 that extend through holes 48 in the drum 2() and'at their inner ends are mounted in a ring 49 itself mounted in a circumferentially grooved collar 50 slidable on the hub of the clutch member 27. On the inner face of the collar 50 are a group of inwardly extending push rods 51 (Fig. 5) extending through holes 52 in the webs 33 and carrying on their free ends rollers 53 that bear against an annular shoulder 30 on the driving clutch member 30. vPivoted at 54 in a hollow boss 55 on the axle housing 10 is a clutch shifter lever'56, the forli of which straddles the Vcollar 46 engaging the circumferential groove ofthe latter, and on the lever 56 is a slidable sleeve 57 raised and lowered by a rod 58 and formed on its lower end with a tooth 59 that cooperates with the upper end ofthe boss to lock the lever 56 in either clutch engaging or clutch disengaging position. )Vith the two vlevers 56 in the 'position shown in Fig. 2,

` are substantially identical with a constructionshown and claimed in an earlier application filed by me on the 24th day ofV October, 1925, Serial No..64,496; and describing the Vmanually operable throw-out mechanism, encircling the drum r20` a short distance outwardly on each side'of its transverse median plane is a thrust or throw-out spider comprising a flat ring 60 carrying inwardly projecting pins 61 engaged with corresponding holes 62 in the central flange of the drum by which the ring 60 is slidably supported on the latter. The ring 60 is provided with inwardly'directed fingers 63 (Fig. 1) that extend through holes 64 formed in Ythe drum sections 20. The inner ends of the fingers 63 abut against an annular shoulder 39 (Fig. 2 side of each of the shiftable clutch members 39. l

Describing next the means for actuating the thrust spiders to disengage the driving clutch members, secured tothe inner face of each of the axle housing sections'10 as by formed onl the vouter* means of T-bolts 65 (Fig. 1) is a cam ring 66 (Fig. 3); On the faceof the cam ring 66 are a plurality of low cams 67 sloping in one direction, andav corresponding plurality of alternately disposed low cams 68 sloping in the reverse direction. The cam ring 66 is also formed with a circular inwardly projecting'flange 69 (Fig. 1), on which is rotatably mounted a cooperating shiftable camring 70.v kOn the outer face of the cam ring 7 0 are formed two groups of alternately arranged oppositely sloping cams 71 and 72 (Fig. 3) which cooperate with the cams 67 and 68 respectively' under turning move-- ments of the cam ring`70 in opposite directions. Eetween the inner face of each cam ring 70 and the outer face of each thrust spider 60 may be interposed an antisfriction thrust bearing 73. For operative purposes only one set of cooperating cams 67, 71 or 68, 72 is required; but each cam ring is preferably equipped with two sets vof oppositely inclined cams for economy of manu facture, since inthatcaSe identical cam rings will serve eitherside of the device. i

On the rvupper side of each shiftable cam ring 70 is a lug 74, to which is pivotally connected by means 'accommodating the lateral shifting movement of the cam ring 70 the yrear end of a forwardly extending link bar 75, this latter extending through a slot or groove 6 in each housing section 20.k A pull spring 77 anchored at one end to the axle housing and at its opposite end to the shiftable cam ring 70 urgesV the cam ring backwardly toidle or inoperative position. The forward endy of each link 75 is, in practice, pivotally connected to a manually operable lever (not shown) equipped with an ordinary segment rackl and locking dog within convenient reach of the driver occupying the seat of the vehicle. f

To operate the above described throw-out, the link 75 is pulled forwardly, and the cooperative action of the cams 71 and 67 shifts the ring 70 inwardly,'the fingers 63 of the latter, through engagement with the shoulder 39 ofthe, driving clutch member 39, disengaging the latter from the driven vclutch member 35, as shown in Fig. 1, thus disconnecting the drive'of the Alocking differential .to either or both axle sections accordingly as onev or both ofthe links 75 are drawn forwardly. `When traveling a Curved path or turning a corner, whereinthe outer wheel and axle overrun the inner wheel and axle, the vdriving clutch member on the outer side is automatically'thrown outof clutch with itscooperating driven clutch member bythe camminglaction of the-teeth of the latter; the clutch engagement being automaticallyrestored by the springs 43 and the cams 37 of the driver spider cooperating with the major cams 40 of the driving clutch members.

ill.

. GSH

l be automatically caniiiiedoutwardlv It it be 'desired to turn the ,vehicle on one rear wheel as a pivot,l this can readily be done by disconnecting' the drive oit bothV the equalizing `and the locking diiieieiitial gearings on one side and maintaining,` the drive lf it be desired to operateapower taire-ori" troni the propeller' shaft 14 or the master gear 17 without thenecessity et removing or jacking up the traction wheels, this can .be'done by disconnecting the Vdrives of both differentialson both sides.

In 7 and 8 of the drawingsl illustrate a. modification: representingsomewhat siinplei'- construction from that above described, and wherein the locking dittereir tial gearing around the equalizing differential gearing,` previously described is replaced b an autoinaticall enffaeino clutch niech a tu h D anisni on each sidevoif. the drum of the equaliziiig differential gearing with independent manually `operable leversl for diseiiragingl the clutches.. ln'these views the equalizing; differential and its separable drives Yto the two shat't sections lare thesaine as, those shown in. Fig. l and the parts thereof are identified by the Vsaine.reference numerals. ln this case, however, since` the locking' di'f- Vferential drum -is not used, the operating,l

levers 56 are applied directly to the collars 50; i

Desciibiiigr'` the eliitch mechanism between the sides olitlie;` equalizing ditlerentiai drum and the axle sections, on Yeach outer Vside oit tliefdiiierential drinn 25 is- Jforrnedgacircular bearing 8O on which is'inounteda laterally shittable driving elutchmeniber 8l that is structurally7 and functionally simi-- lar to, and encircles the driving,F clutch ineinber through which the rotative effort of the equalizing diiierential gearing -is Ytransinitted to the axle sections. ,-.The inner side of the driving clutch member 8l isA` forined with radial socketshaving inclined sides,l

similar to the radial sockets 3l of the shittable clutch member 8O shown in Fig. 4, and these sockets are engaged `by radial lugs 82- haviiig correspondingly inclined or cainiiied side walls 82. The outer sideV of each sli-iiftable clutchV ineniber is equipped with clutch teeth ifi-that" are adapted to engage u corresponding clutch teeth V8 4: -on a'drive'n Aclutch ineinbe-r VSathatv isf mounted' on Athe hub of the. inner ydriven clutch ineinber 27 and .inay be secured 'to the latter as by serewgboits 86. vThe web of thedriven clutch member 85 is termed with holes 87 to perinitm passage therethrough of the thrust rods 5l.. Frein the'foregroiiig' itgwill be seen that when the diiterential druin 25 lugsBZ into clutch; engagementy vis toV sl v through the inner drivencluteh members-27 1' to which` the outer driven clutch ineinbers be held disengaged troni `their cooperating driven clutch members .85 by lniechanisin siniilar to that ipreviously lescri'bed, and consisting, in each case, of a clutch shifter 88, the iorlr of wliichstraddles the' groove in the ciutchineinber 8l, the clutch shifter llever 88 being` conneetedtoa suitable opeiatiiip, lever ,vithin reach ojl" the driver and equipped with'r a detent, similar to that shown in Fig. 2 in connection with the lever 56, to locl(VV the sainein the cliitclidisengi'aging position against the thrust of the eain lugs ,82. l

TWhen running on the; eqiializiiig differential alone, the clutch shifter 5G is released, and the clutch shifter 88 is locked to niain`v taiii the Vouter clutches disengaged. Vihen running` on the outer clutch mechanism aliene the conditions Voi the two clutch shifter levers land 88 are reversed; that drive is then through the outer clutch inemliers 8l and 85,'the lever 56 being;A niaiiitained loci-red so as to hold theinnerclutcli ineiiibei's 3() and 27 separated. It' desired, both clutch shifter levers'niay be released,

[and the drive will then be distributed through the equalizing differential inechaisin and the outer clutch drive. On the other hand, `with both clutch shifter levers locked, both drives Vare disconnected, as

shown in Fig. 7, and the mechanism is in a condition to permit the operation of a power' take-off 'from the propeller shaft without reinovingj or jacking up thetraction wheels driven by the axle sections 13.

rlhis apparatus can.'q

be manipulated toetlect a turning inovenient oi the vehicle the lever y8S is released and the90 outer wheel is in a one toene ratio to the speedoi the differential pear., insteadotl in a two to` one speed ra 'o a inthe caseofV the standard equaliz ,diillcrential when the inner wheel is held Oainstturning.

Both of the Y, auto y ticfally v,engaging clutch mechanismsr herein shown and described are substantially like that disclosed and claimed in an earlier application tiled by ine April l2. 1926, Serial No. 101,298 in which application saidv clutch ineclianisn'i is shown embodiedv in vreaifand` side power taire-Otis. i i

ln construing `the Vclaiinsl hereunto appended, it is to `be.understood*thatfthe eniifthe A Vdrivenclutch nieinbers 85. and tl'iiszdri've will be transmitted to theanleseetions bodinieiits ofv thefinventionf herein shown and described' are illustrative only and not limiting, and may be `variously inoditied and changed as special circumstances and equipments may require Without involving any departure from the principles involved o r sacrificing any of the advantages and utilities secured by the invention.

I claiml. ln a power transmitting mechanism, the combination With alined shaft sections, of an equalizing differential gearing mounted on said shaft sections, means drivingly connecting said gearing to said shaft sections, a clutch mechanism mounted on and connected to said shaft sections, a driving means common to both said differential gearing and said clutch mechanism, means for rendering idle said connecting means, and means for rendering idle said clutch mechanism.

2. In a power transmitting mechanism, the combination with alined shaft sections, of an equalizing differential gearing mounted on said shaft sections, clutch mechanism connecting said gearing to said shaft sections. other clutch mechanismencircling said differential gearing and connected to said shaft sections, a driving means for said differential mechanism and said other clutch mechanism common to both, and independent means for operating said respective clutch mechanisms.

In a power transmitting mechanism, the combination with alined shaft sections, of an equalizing differential gearing mounted. on said shaft sections, independent clutches connecting` both sides of said gearing to the respective shaft sections, other independent clutches encircling said differential gearing and connected to the respective shaft sections, a driving means for said differential gearing and said other clutches common to both, and independently operable means for shifting said clutches.

4. In a power transmitting mechanism, the combination with alined shaft sections, of an equalizing differential gearing mounted on said shaft sections, independent automatically engaging clutches connecting both sides of said gearing to the respective shaft sections, other independent automatically engaging clutches encircling said differential gearing and connected to the respective shaft sections, a driving means for said differential gearing and said other clutches common to both, and independently operable means for disengaging said clutches.

5. ln a differential mechanism for transmitting power, the combination with alined shaft sections, of an equalizing differential gearing including a pair of gears rotatably mounted on the inner ends of said shaft sections, driven clutch members keyed to said shaft sections, driving clutch members on said shaft sections between the hubs of said gears and said driven clutch members, cooperating means on said hubs and said driving clutch members by which the latter are rotated and shifted into engagement With said driven clutch members, and manually operable means for disengaging said driving and driven clutch members. v

6. In a differential mechanism of the character described, the combination With alined shaft sections, of an equalizing differential mechanism mounted on said shaft sections, a 'locking differential mechanism mounted on said shaft sections, means for rotating said mechanisms, means drivingly connecting both said mechanisms to said shaft sections,rand means for disconnecting the drives of either or both said mechanisms to'said shaft sections.

7. In a differential mechanism of the character described, the combination With alined shaft sections, of an equalizing differential mechanism mounted on'said shaft sections,

a' locking differential mechanism mounted on said shaft sections, means for rotating said mechanisms, means drivingly connecting the opposite sides of both said mechanisms toV izing mechanism vto the respective shaft sec-A tions, other automatic means for drivingly connecting the opposite sides of said locking mechanism to the respective shaft sections, and means for rendering either or .both of said automatic means inoperative.

9. In a differential mechanism of the character described, the combination with alined shaft sections, of an equalizing differential mechanism mounted on the proximate ends of said shaft sections, `a locking differential mechanism surrounding said equalizing mechanism, a rotating means for said mechanisms common to both, and disconnectible means for transmitting the rotative movements of both said mechanisms to said shaft sections.

10. In a dierential mechanism of the character described, the combination with alined shaft sections, of an equalizing differential mechanism mounted on the proximate ends of said shaft sections, a locking differential mechanism surrounding said equalizing mechanism, a rotating means forsaid mechanisms common to both, means, including automatically engaging clutch members, for transmittingv the rotative movements of both said mechanisms to said shaft sections, and manually operable means forv disengaging said clutch members.

FRANK M. LEVHS. 

